/* $VER: unlzx.c 1.0 (22.2.98) */
/* Created: 11.2.98 */
/* Added Pipe support to read from stdin (03.4.01, Erik Meusel)           */

/* LZX Extract in (supposedly) portable C.                                */

/* ********************* WINDOWS PORTING NOTES STARTS *********************/

/* Ported to Windows Platform by Stefano Coletta on 22.5.02               */
/* creator@mindcreations.com or visit http://creator.mindcreations.com    */

/* Changes to original code include:                                      */
/* - Using #include <direct.h> to substitute the mkdir() function call    */
/* - Added #include "getopt.h" to support getopt() function               */

/* Compile with:                                                          */
/* Microsoft Visual Studio 6.0 SP5 using supplied project file            */

/* ********************** WINDOWS PORTING NOTES END ***********************/

/* Thanks to Dan Fraser for decoding the coredumps and helping me track   */
/* down some HIDEOUSLY ANNOYING bugs.                                     */

/* Everything is accessed as unsigned char's to try and avoid problems    */
/* with byte order and alignment. Most of the decrunch functions          */
/* encourage overruns in the buffers to make things as fast as possible.  */
/* All the time is taken up in crc_calc() and decrunch() so they are      */
/* pretty damn optimized. Don't try to understand this program.           */

/* ---------------------------------------------------------------------- */

/* - minimal UAE specific version 13-14.06.2007 by Toni Wilen */

#include "sysconfig.h"
#include "zfile.h"
#include "zarchive.h"

/* ---------------------------------------------------------------------- */

static unsigned char* source;
static unsigned char* destination;
static unsigned char* source_end;
static unsigned char* destination_end;

static uint decrunch_method;
static uint decrunch_length;
static uint last_offset;
static uint global_control;
static int global_shift;

static unsigned char offset_len[8];
static unsigned short offset_table[128];
static unsigned char huffman20_len[20];
static unsigned short huffman20_table[96];
static unsigned char literal_len[768];
static unsigned short literal_table[5120];

/* ---------------------------------------------------------------------- */

static uint sum;

static const uint crc_table[256] =
{
    0x00000000, 0x77073096, 0xEE0E612C, 0x990951BA, 0x076DC419, 0x706AF48F,
    0xE963A535, 0x9E6495A3, 0x0EDB8832, 0x79DCB8A4, 0xE0D5E91E, 0x97D2D988,
    0x09B64C2B, 0x7EB17CBD, 0xE7B82D07, 0x90BF1D91, 0x1DB71064, 0x6AB020F2,
    0xF3B97148, 0x84BE41DE, 0x1ADAD47D, 0x6DDDE4EB, 0xF4D4B551, 0x83D385C7,
    0x136C9856, 0x646BA8C0, 0xFD62F97A, 0x8A65C9EC, 0x14015C4F, 0x63066CD9,
    0xFA0F3D63, 0x8D080DF5, 0x3B6E20C8, 0x4C69105E, 0xD56041E4, 0xA2677172,
    0x3C03E4D1, 0x4B04D447, 0xD20D85FD, 0xA50AB56B, 0x35B5A8FA, 0x42B2986C,
    0xDBBBC9D6, 0xACBCF940, 0x32D86CE3, 0x45DF5C75, 0xDCD60DCF, 0xABD13D59,
    0x26D930AC, 0x51DE003A, 0xC8D75180, 0xBFD06116, 0x21B4F4B5, 0x56B3C423,
    0xCFBA9599, 0xB8BDA50F, 0x2802B89E, 0x5F058808, 0xC60CD9B2, 0xB10BE924,
    0x2F6F7C87, 0x58684C11, 0xC1611DAB, 0xB6662D3D, 0x76DC4190, 0x01DB7106,
    0x98D220BC, 0xEFD5102A, 0x71B18589, 0x06B6B51F, 0x9FBFE4A5, 0xE8B8D433,
    0x7807C9A2, 0x0F00F934, 0x9609A88E, 0xE10E9818, 0x7F6A0DBB, 0x086D3D2D,
    0x91646C97, 0xE6635C01, 0x6B6B51F4, 0x1C6C6162, 0x856530D8, 0xF262004E,
    0x6C0695ED, 0x1B01A57B, 0x8208F4C1, 0xF50FC457, 0x65B0D9C6, 0x12B7E950,
    0x8BBEB8EA, 0xFCB9887C, 0x62DD1DDF, 0x15DA2D49, 0x8CD37CF3, 0xFBD44C65,
    0x4DB26158, 0x3AB551CE, 0xA3BC0074, 0xD4BB30E2, 0x4ADFA541, 0x3DD895D7,
    0xA4D1C46D, 0xD3D6F4FB, 0x4369E96A, 0x346ED9FC, 0xAD678846, 0xDA60B8D0,
    0x44042D73, 0x33031DE5, 0xAA0A4C5F, 0xDD0D7CC9, 0x5005713C, 0x270241AA,
    0xBE0B1010, 0xC90C2086, 0x5768B525, 0x206F85B3, 0xB966D409, 0xCE61E49F,
    0x5EDEF90E, 0x29D9C998, 0xB0D09822, 0xC7D7A8B4, 0x59B33D17, 0x2EB40D81,
    0xB7BD5C3B, 0xC0BA6CAD, 0xEDB88320, 0x9ABFB3B6, 0x03B6E20C, 0x74B1D29A,
    0xEAD54739, 0x9DD277AF, 0x04DB2615, 0x73DC1683, 0xE3630B12, 0x94643B84,
    0x0D6D6A3E, 0x7A6A5AA8, 0xE40ECF0B, 0x9309FF9D, 0x0A00AE27, 0x7D079EB1,
    0xF00F9344, 0x8708A3D2, 0x1E01F268, 0x6906C2FE, 0xF762575D, 0x806567CB,
    0x196C3671, 0x6E6B06E7, 0xFED41B76, 0x89D32BE0, 0x10DA7A5A, 0x67DD4ACC,
    0xF9B9DF6F, 0x8EBEEFF9, 0x17B7BE43, 0x60B08ED5, 0xD6D6A3E8, 0xA1D1937E,
    0x38D8C2C4, 0x4FDFF252, 0xD1BB67F1, 0xA6BC5767, 0x3FB506DD, 0x48B2364B,
    0xD80D2BDA, 0xAF0A1B4C, 0x36034AF6, 0x41047A60, 0xDF60EFC3, 0xA867DF55,
    0x316E8EEF, 0x4669BE79, 0xCB61B38C, 0xBC66831A, 0x256FD2A0, 0x5268E236,
    0xCC0C7795, 0xBB0B4703, 0x220216B9, 0x5505262F, 0xC5BA3BBE, 0xB2BD0B28,
    0x2BB45A92, 0x5CB36A04, 0xC2D7FFA7, 0xB5D0CF31, 0x2CD99E8B, 0x5BDEAE1D,
    0x9B64C2B0, 0xEC63F226, 0x756AA39C, 0x026D930A, 0x9C0906A9, 0xEB0E363F,
    0x72076785, 0x05005713, 0x95BF4A82, 0xE2B87A14, 0x7BB12BAE, 0x0CB61B38,
    0x92D28E9B, 0xE5D5BE0D, 0x7CDCEFB7, 0x0BDBDF21, 0x86D3D2D4, 0xF1D4E242,
    0x68DDB3F8, 0x1FDA836E, 0x81BE16CD, 0xF6B9265B, 0x6FB077E1, 0x18B74777,
    0x88085AE6, 0xFF0F6A70, 0x66063BCA, 0x11010B5C, 0x8F659EFF, 0xF862AE69,
    0x616BFFD3, 0x166CCF45, 0xA00AE278, 0xD70DD2EE, 0x4E048354, 0x3903B3C2,
    0xA7672661, 0xD06016F7, 0x4969474D, 0x3E6E77DB, 0xAED16A4A, 0xD9D65ADC,
    0x40DF0B66, 0x37D83BF0, 0xA9BCAE53, 0xDEBB9EC5, 0x47B2CF7F, 0x30B5FFE9,
    0xBDBDF21C, 0xCABAC28A, 0x53B39330, 0x24B4A3A6, 0xBAD03605, 0xCDD70693,
    0x54DE5729, 0x23D967BF, 0xB3667A2E, 0xC4614AB8, 0x5D681B02, 0x2A6F2B94,
    0xB40BBE37, 0xC30C8EA1, 0x5A05DF1B, 0x2D02EF8D
};

/* ---------------------------------------------------------------------- */

static const unsigned char table_one[32] =
{
    0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 7, 8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13, 14, 14
};

static const uint table_two[32] =
{
    0, 1, 2, 3, 4, 6, 8, 12, 16, 24, 32, 48, 64, 96, 128, 192, 256, 384, 512, 768, 1024,
    1536, 2048, 3072, 4096, 6144, 8192, 12288, 16384, 24576, 32768, 49152
};

static const uint table_three[16] =
{
    0, 1, 3, 7, 15, 31, 63, 127, 255, 511, 1023, 2047, 4095, 8191, 16383, 32767
};

static const unsigned char table_four[34] =
{
    0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,
    0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16
};

/* ---------------------------------------------------------------------- */

/* Possible problems with 64 bit machines here. It kept giving warnings   */
/* for people so I changed back to ~.                                     */

static void crc_calc(unsigned char* memory, uint length)
{
    register uint temp;

    if (length)
    {
        temp = ~sum; /* was (sum ^ 4294967295) */
        do
        {
            temp = crc_table[(*memory++ ^ temp) & 255] ^ (temp >> 8);
        }
        while (--length);
        sum = ~temp; /* was (temp ^ 4294967295) */
    }
}

/* ---------------------------------------------------------------------- */

/* Build a fast huffman decode table from the symbol bit lengths.         */
/* There is an alternate algorithm which is faster but also more complex. */

static int make_decode_table(int number_symbols, int table_size,
    unsigned char* length, unsigned short* table)
{
    register unsigned char bit_num = 0;
    register int symbol;
    uint leaf; /* could be a register */
    uint table_mask, bit_mask, pos, fill, next_symbol, reverse;
    int abort = 0;

    pos = 0; /* consistantly used as the current position in the decode table */

    bit_mask = table_mask = 1 << table_size;

    bit_mask >>= 1; /* don't do the first number */
    bit_num++;

    while ((!abort) && (bit_num <= table_size))
    {
        for (symbol = 0; symbol < number_symbols; symbol++)
        {
            if (length[symbol] == bit_num)
            {
                reverse = pos; /* reverse the order of the position's bits */
                leaf = 0;
                fill = table_size;
                do /* reverse the position */
                {
                    leaf = (leaf << 1) + (reverse & 1);
                    reverse >>= 1;
                }
                while (--fill);
                if ((pos += bit_mask) > table_mask)
                {
                    abort = 1;
                    break; /* we will overrun the table! abort! */
                }
                fill = bit_mask;
                next_symbol = 1 << bit_num;
                do
                {
                    table[leaf] = symbol;
                    leaf += next_symbol;
                }
                while (--fill);
            }
        }
        bit_mask >>= 1;
        bit_num++;
    }

    if ((!abort) && (pos != table_mask))
    {
        for (symbol = pos; symbol < table_mask; symbol++) /* clear the rest of the table */
        {
            reverse = symbol; /* reverse the order of the position's bits */
            leaf = 0;
            fill = table_size;
            do /* reverse the position */
            {
                leaf = (leaf << 1) + (reverse & 1);
                reverse >>= 1;
            }
            while (--fill);
            table[leaf] = 0;
        }
        next_symbol = table_mask >> 1;
        pos <<= 16;
        table_mask <<= 16;
        bit_mask = 32768;

        while ((!abort) && (bit_num <= 16))
        {
            for (symbol = 0; symbol < number_symbols; symbol++)
            {
                if (length[symbol] == bit_num)
                {
                    reverse = pos >> 16; /* reverse the order of the position's bits */
                    leaf = 0;
                    fill = table_size;
                    do /* reverse the position */
                    {
                        leaf = (leaf << 1) + (reverse & 1);
                        reverse >>= 1;
                    }
                    while (--fill);
                    for (fill = 0; fill < bit_num - table_size; fill++)
                    {
                        if (table[leaf] == 0)
                        {
                            table[(next_symbol << 1)] = 0;
                            table[(next_symbol << 1) + 1] = 0;
                            table[leaf] = next_symbol++;
                        }
                        leaf = table[leaf] << 1;
                        leaf += (pos >> (15 - fill)) & 1;
                    }
                    table[leaf] = symbol;
                    if ((pos += bit_mask) > table_mask)
                    {
                        abort = 1;
                        break; /* we will overrun the table! abort! */
                    }
                }
            }
            bit_mask >>= 1;
            bit_num++;
        }
    }
    if (pos != table_mask)
        abort = 1;                    /* the table is incomplete! */

    return (abort);
}

/* ---------------------------------------------------------------------- */

/* Read and build the decrunch tables. There better be enough data in the */
/* source buffer or it's stuffed. */

static int read_literal_table()
{
    register uint control;
    register int shift;
    uint temp; /* could be a register */
    uint symbol, pos, count, fix, max_symbol;
    int abort = 0;

    control = global_control;
    shift = global_shift;

    if (shift < 0) /* fix the control word if necessary */
    {
        shift += 16;
        control += *source++ << (8 + shift);
        control += *source++ << shift;
    }

    /* read the decrunch method */

    decrunch_method = control & 7;
    control >>= 3;
    if ((shift -= 3) < 0)
    {
        shift += 16;
        control += *source++ << (8 + shift);
        control += *source++ << shift;
    }

    /* Read and build the offset huffman table */

    if ((!abort) && (decrunch_method == 3))
    {
        for (temp = 0; temp < 8; temp++)
        {
            offset_len[temp] = control & 7;
            control >>= 3;
            if ((shift -= 3) < 0)
            {
                shift += 16;
                control += *source++ << (8 + shift);
                control += *source++ << shift;
            }
        }
        abort = make_decode_table(8, 7, offset_len, offset_table);
    }

    /* read decrunch length */

    if (!abort)
    {
        decrunch_length = (control & 255) << 16;
        control >>= 8;
        if ((shift -= 8) < 0)
        {
            shift += 16;
            control += *source++ << (8 + shift);
            control += *source++ << shift;
        }
        decrunch_length += (control & 255) << 8;
        control >>= 8;
        if ((shift -= 8) < 0)
        {
            shift += 16;
            control += *source++ << (8 + shift);
            control += *source++ << shift;
        }
        decrunch_length += (control & 255);
        control >>= 8;
        if ((shift -= 8) < 0)
        {
            shift += 16;
            control += *source++ << (8 + shift);
            control += *source++ << shift;
        }
    }

    /* read and build the huffman literal table */

    if ((!abort) && (decrunch_method != 1))
    {
        pos = 0;
        fix = 1;
        max_symbol = 256;

        do
        {
            for (temp = 0; temp < 20; temp++)
            {
                huffman20_len[temp] = control & 15;
                control >>= 4;
                if ((shift -= 4) < 0)
                {
                    shift += 16;
                    control += *source++ << (8 + shift);
                    control += *source++ << shift;
                }
            }
            abort = make_decode_table(20, 6, huffman20_len, huffman20_table);

            if (abort)
                break;        /* argh! table is corrupt! */

            do
            {
                if ((symbol = huffman20_table[control & 63]) >= 20)
                {
                    do /* symbol is longer than 6 bits */
                    {
                        symbol = huffman20_table[((control >> 6) & 1) + (symbol << 1)];
                        if (!shift--)
                        {
                            shift += 16;
                            control += *source++ << 24;
                            control += *source++ << 16;
                        }
                        control >>= 1;
                    }
                    while (symbol >= 20);
                    temp = 6;
                }
                else
                {
                    temp = huffman20_len[symbol];
                }
                control >>= temp;
                if ((shift -= temp) < 0)
                {
                    shift += 16;
                    control += *source++ << (8 + shift);
                    control += *source++ << shift;
                }
                switch (symbol)
                {
                    case 17:
                    case 18:
                    {
                        if (symbol == 17)
                        {
                            temp = 4;
                            count = 3;
                        }
                        else /* symbol == 18 */
                        {
                            temp = 6 - fix;
                            count = 19;
                        }
                        count += (control & table_three[temp]) + fix;
                        control >>= temp;
                        if ((shift -= temp) < 0)
                        {
                            shift += 16;
                            control += *source++ << (8 + shift);
                            control += *source++ << shift;
                        }
                        while ((pos < max_symbol) && (count--))
                            literal_len[pos++] = 0;
                        break;
                    }
                    case 19:
                    {
                        count = (control & 1) + 3 + fix;
                        if (!shift--)
                        {
                            shift += 16;
                            control += *source++ << 24;
                            control += *source++ << 16;
                        }
                        control >>= 1;
                        if ((symbol = huffman20_table[control & 63]) >= 20)
                        {
                            do /* symbol is longer than 6 bits */
                            {
                                symbol = huffman20_table[((control >> 6) & 1) + (symbol << 1)];
                                if (!shift--)
                                {
                                    shift += 16;
                                    control += *source++ << 24;
                                    control += *source++ << 16;
                                }
                                control >>= 1;
                            }
                            while (symbol >= 20);
                            temp = 6;
                        }
                        else
                        {
                            temp = huffman20_len[symbol];
                        }
                        control >>= temp;
                        if ((shift -= temp) < 0)
                        {
                            shift += 16;
                            control += *source++ << (8 + shift);
                            control += *source++ << shift;
                        }
                        symbol = table_four[literal_len[pos] + 17 - symbol];
                        while ((pos < max_symbol) && (count--))
                            literal_len[pos++] = symbol;
                        break;
                    }
                    default:
                    {
                        symbol = table_four[literal_len[pos] + 17 - symbol];
                        literal_len[pos++] = symbol;
                        break;
                    }
                }
            }
            while (pos < max_symbol);
            fix--;
            max_symbol += 512;
        }
        while (max_symbol == 768);

        if (!abort)
            abort = make_decode_table(768, 12, literal_len, literal_table);
    }

    global_control = control;
    global_shift = shift;

    return (abort);
}

/* ---------------------------------------------------------------------- */

/* Fill up the decrunch buffer. Needs lots of overrun for both destination */
/* and source buffers. Most of the time is spent in this routine so it's  */
/* pretty damn optimized. */

static void decrunch()
{
    register uint control;
    register int shift;
    uint temp; /* could be a register */
    uint symbol, count;
    unsigned char* string;

    control = global_control;
    shift = global_shift;

    do
    {
        if ((symbol = literal_table[control & 4095]) >= 768)
        {
            control >>= 12;
            if ((shift -= 12) < 0)
            {
                shift += 16;
                control += *source++ << (8 + shift);
                control += *source++ << shift;
            }
            do /* literal is longer than 12 bits */
            {
                symbol = literal_table[(control & 1) + (symbol << 1)];
                if (!shift--)
                {
                    shift += 16;
                    control += *source++ << 24;
                    control += *source++ << 16;
                }
                control >>= 1;
            }
            while (symbol >= 768);
        }
        else
        {
            temp = literal_len[symbol];
            control >>= temp;
            if ((shift -= temp) < 0)
            {
                shift += 16;
                control += *source++ << (8 + shift);
                control += *source++ << shift;
            }
        }
        if (symbol < 256)
        {
            *destination++ = symbol;
        }
        else
        {
            symbol -= 256;
            count = table_two[temp = symbol & 31];
            temp = table_one[temp];
            if ((temp >= 3) && (decrunch_method == 3))
            {
                temp -= 3;
                count += ((control & table_three[temp]) << 3);
                control >>= temp;
                if ((shift -= temp) < 0)
                {
                    shift += 16;
                    control += *source++ << (8 + shift);
                    control += *source++ << shift;
                }
                count += (temp = offset_table[control & 127]);
                temp = offset_len[temp];
            }
            else
            {
                count += control & table_three[temp];
                if (!count)
                    count = last_offset;
            }
            control >>= temp;
            if ((shift -= temp) < 0)
            {
                shift += 16;
                control += *source++ << (8 + shift);
                control += *source++ << shift;
            }
            last_offset = count;

            count = table_two[temp = (symbol >> 5) & 15] + 3;
            temp = table_one[temp];
            count += (control & table_three[temp]);
            control >>= temp;
            if ((shift -= temp) < 0)
            {
                shift += 16;
                control += *source++ << (8 + shift);
                control += *source++ << shift;
            }
            string = destination - last_offset;
            do
            {
                *destination++ = *string++;
            }
            while (--count);
        }
    }
    while ((destination < destination_end) && (source < source_end));

    global_control = control;
    global_shift = shift;
}

struct zfile* archive_access_lzx(struct znode* zn)
{
    uint startpos;
    struct znode* znfirst, * znlast;
    struct zfile* zf = zn->volume->archive;
    struct zfile* dstf, * newzf;
    byte* buf, * dbuf;
    uint compsize, unpsize;

    dstf = nullptr;
    buf = dbuf = nullptr;
    newzf = nullptr;

    /* find first file in compressed block */
    unpsize = 0;
    znfirst = zn;
    while (znfirst->prev)
    {
        struct znode* zt = znfirst->prev;
        if (!zt || zt->offset != 0)
            break;
        znfirst = zt;
        unpsize += znfirst->size;
    }
    /* find last file in compressed block */
    znlast = zn;
    while (znlast)
    {
        unpsize += znlast->size;
        if (znlast->offset != 0)
            break;
        znlast = znlast->next;
    }
    if (!znlast)
        return nullptr;
    /* start offset to compressed block */
    startpos = znlast->offset;
    compsize = znlast->packedsize;
    zfile_fseek(zf, startpos, SEEK_SET);
    buf = xmalloc(byte, compsize);
    zfile_fread(buf, compsize, 1, zf);
    dbuf = xcalloc(byte, unpsize);

    /* unpack complete block */
    memset(offset_len, 0, sizeof offset_len);
    memset(literal_len, 0, sizeof literal_len);
    sum = 0;
    source = buf;
    source_end = buf + compsize;
    global_control = 0;
    global_shift = -16;
    last_offset = 1;
    destination = dbuf;
    if (compsize == unpsize)
    {
        memcpy(dbuf, buf, unpsize);
    }
    else
    {
        while (unpsize > 0)
        {
            byte* pdest = destination;
            if (!read_literal_table())
            {
                destination_end = destination + decrunch_length;
                decrunch();
                unpsize -= decrunch_length;
                crc_calc(pdest, decrunch_length);
            }
            else
            {
                Logger::Write(L"LZX corrupt compressed data %s\n", zn->name);
                goto end;
            }
        }
    }
    /* pre-cache all files we just decompressed */
    for (;;)
    {
        if (znfirst->size && !znfirst->f)
        {
            dstf = zfile_fopen_empty(zf, znfirst->name, znfirst->size);
            zfile_fwrite(dbuf + znfirst->offset2, znfirst->size, 1, dstf);
            znfirst->f = dstf;
            if (znfirst == zn)
                newzf = zfile_dup(dstf);
        }
        if (znfirst == znlast)
            break;
        znfirst = znfirst->next;
    }
end:
    free(buf);
    free(dbuf);
    return newzf;
}

struct zvolume* archive_directory_lzx(struct zfile* in_file)
{
    uint temp;
    uint total_pack = 0;
    uint total_unpack = 0;
    uint total_files = 0;
    uint merge_size = 0;
    int actual;
    int abort;
    int result = 1; /* assume an error */
    struct zvolume* zv;
    struct znode* zn;
    struct zarchive_info zai;
    struct tm tm;
    uint crc;
    uint pack_size;
    uint unpack_size;
    unsigned char archive_header[31];
    char header_filename[256];
    char header_comment[256];

    if (zfile_fread(archive_header, 1, 10, in_file) != 10)
        return 0;
    if (memcmp(archive_header, "LZX", 3))
        return 0;
    zv = zvolume_alloc(in_file, ArchiveFormatLZX, nullptr, nullptr);

    do
    {
        abort = 1; /* assume an error */
        actual = zfile_fread(archive_header, 1, 31, in_file);
        if (!zfile_ferror(in_file))
        {
            if (actual) /* 0 is normal and means EOF */
            {
                if (actual == 31)
                {
                    sum = 0; /* reset CRC */
                    crc = (archive_header[29] << 24) + (archive_header[28] << 16) + (archive_header[27] << 8) + archive_header[26];
                    archive_header[29] = 0; /* Must set the field to 0 before calculating the crc */
                    archive_header[28] = 0;
                    archive_header[27] = 0;
                    archive_header[26] = 0;
                    crc_calc(archive_header, 31);
                    temp = archive_header[30]; /* filename length */
                    actual = zfile_fread(header_filename, 1, temp, in_file);
                    if (!zfile_ferror(in_file))
                    {
                        if (actual == temp)
                        {
                            header_filename[temp] = 0;
                            crc_calc((unsigned char*)header_filename, temp);
                            temp = archive_header[14]; /* comment length */
                            actual = zfile_fread(header_comment, 1, temp, in_file);
                            if (!zfile_ferror(in_file))
                            {
                                if (actual == temp)
                                {
                                    header_comment[temp] = 0;
                                    crc_calc((unsigned char*)header_comment, temp);
                                    if (sum == crc)
                                    {
                                        uint year, month, day;
                                        uint hour, minute, second;
                                        unsigned char attributes;
                                        attributes = archive_header[0]; /* file protection modes */
                                        unpack_size = (archive_header[5] << 24) + (archive_header[4] << 16) + (archive_header[3] << 8) + archive_header[2]; /* unpack size */
                                        pack_size = (archive_header[9] << 24) + (archive_header[8] << 16) + (archive_header[7] << 8) + archive_header[6]; /* packed size */
                                        temp = (archive_header[18] << 24) + (archive_header[19] << 16) + (archive_header[20] << 8) + archive_header[21]; /* date */
                                        year = ((temp >> 17) & 63) + 1970;
                                        month = (temp >> 23) & 15;
                                        day = (temp >> 27) & 31;
                                        hour = (temp >> 12) & 31;
                                        minute = (temp >> 6) & 63;
                                        second = temp & 63;

                                        memset(&zai, 0, sizeof zai);
                                        zai.name = Unicode::au(header_filename);
                                        if (header_comment[0])
                                            zai.comment = Unicode::au(header_comment);
                                        zai.flags |= (attributes & 32) ? 0x80 : 0;
                                        zai.flags |= (attributes & 64) ? 0x40 : 0;
                                        zai.flags |= (attributes & 128) ? 0x20 : 0;
                                        zai.flags |= (attributes & 16) ? 0x10 : 0;
                                        zai.flags |= (attributes & 1) ? 0x08 : 0;
                                        zai.flags |= (attributes & 2) ? 0x04 : 0;
                                        zai.flags |= (attributes & 8) ? 0x02 : 0;
                                        zai.flags |= (attributes & 4) ? 0x01 : 0;
                                        zai.flags ^= 15;
                                        memset(&tm, 0, sizeof tm);
                                        tm.tm_hour = hour;
                                        tm.tm_min = minute;
                                        tm.tm_sec = second;
                                        tm.tm_year = year - 1900;
                                        tm.tm_mon = month;
                                        tm.tm_mday = day;
                                        zai.t = mktime(&tm);
                                        zai.size = unpack_size;
                                        zn = zvolume_addfile_abs(zv, &zai);
                                        zn->offset2 = merge_size;
                                        free(zai.name);
                                        free(zai.comment);

                                        total_pack += pack_size;
                                        total_unpack += unpack_size;
                                        total_files++;
                                        merge_size += unpack_size;

                                        if (pack_size) /* seek past the packed data */
                                        {
                                            merge_size = 0;
                                            zn->offset = zfile_ftell(in_file);
                                            zn->packedsize = pack_size;
                                            if (!zfile_fseek(in_file, pack_size, SEEK_CUR))
                                            {
                                                abort = 0; /* continue */
                                            }
                                        }
                                        else
                                            abort = 0;  /* continue */

                                        // Logger::Write (L"unp=%6d mrg=%6d pack=%6d off=%6d %s\n", unpack_size, merge_size, pack_size, zn->offset, zai.name);
                                    }
                                }
                            }
                        }
                    }
                }
            }
            else
            {
                result = 0; /* normal termination */
            }
        }
    }
    while (!abort);

    return zv;
}